package Experiment.Case4;

public class Text {
    public static void main(String[] args) {
        System.out.println("陈杰202012900203");
        computer pc=new computer();
        Udisk u=new Udisk();
        Mouse m=new Mouse();
        pc.usb=u;
        pc.externalDeviceWorld();
        pc.usb=m;
        pc.externalDeviceWorld();
    }
}
